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  <title>Document</title>
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  <script>
    // function fn(x, y) {
    //   x = x || 0
    //   y = y || 0
    //   console.log(x + y)
    // }
    // fn()
    let age = 18
    console.log(false && age++)
    console.log(age)

    console.log(true || age++)
    console.log(age)
  </script>
</body>

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